Project Summary New and emerging tobacco products (NETPs) are low priced, often flavored products including but not limited to hookah and electronic cigarettes (e-cigarettes) and are not, yet regulated the same way as cigarettes are. NETP usage has been increasing rapidly in recent years, above all e-cigarettes, which now have become the most commonly used tobacco product among the younger population in the US. This trend is supported by an assumption and promotion as such that, NETP use is harmless and a safe alternative to cigarette smoking, despite a lack of sufficient health science data. The airway mucus secretion layer is most exposed to biological and artificial components that are part of smoke and vapors and chronic smoking changes the (protein) composition of the airway mucus, ultimately leading to lung disease, signified by impaired innate defense and inflammation. We recently have shown that the airway secretome of e-cigarette users is distinctly altered in comparison to cigarette and non-smokers. In addition, our data indicates that innate immune proteins are particularly effected in e-cigarette user's airways. This impact on the airway proteome, is mediated in part by protein modifications caused by smoke and vapor constituents such as reactive aldehydes, e.g. acetaldehyde, acrolein and crotonaldehyde that form adducts that can impact protein function. In fact, our preliminary studies are showing that airway protein function can be disrupted by exposure to smokes and vapors. Common effect biomarker research is investigating differential protein levels and cannot detect changes in proteins that stay at constant expression. Our new approach however, can identify protein modifications caused by chemical modification. To compare the effects of NETPs and their constituents to those of cigarettes and what potential unique effects NETPs have on the airway physiology, we will analyze protein modifications resulting from NETP and cigarette smokes/vapors. Since the use of NETPs is a rather new trend, data on the long term effects of NETPs, and particularly on exclusive NETP users' health is still unknown. The identification of immediate effects of NETP smokes/vapors in causing protein modifications in users' airways will be useful for future functional analyses and may help in predicting potential long term health effects. Using qualitative and quantitative proteomics to analyze human samples we propose to determine protein modifications as new biomarkers of NETP use and toxicity. Ultimately, our approach will have the potential to inform regulations on tobacco product safety by identifying unique NETP effect markers and assessing the health risks of NETP versus cigarette usage.